macros: Changes to 'master'

[Jon TURNEY]

 xorg-macros.m4.in |   34 +++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

New commits:
commit a1809fde56e45639556a44fd3c3ef9213204c5a9
Author: Jon TURNEY <jon.turney at dronecode.org.uk>
Date:   Mon Jan 2 19:42:10 2012 +0000

    Cache the results of checking compiler flag support in XORG_TESTSET_CFLAG
    
    Since checking all those warning flags takes an amount of time I find irritating,
    here is an attempt at caching the results of checking compiler warning flag support
    
    A couple of aspects which need definitely need review or testing:
    
    * I've tried to get things right when not the first flag in the list of alternates is
    supported, but this really needs testing with a compiler other than gcc
    
    * The cache variable naming policy is a bit opaque me, so the names used may need corecting
    
    * I've tried to be careful, but who knows what portability sins I have committed :-)
    
    This change reduces the time to run the ./configure script produced from a configure.ac
    containing just
    
    AC_INIT([test], 1.0)
    XORG_COMPILER_FLAGS
    XORG_CWARNFLAGS
    XORG_STRICT_OPTION
    AC_OUTPUT()
    
    from ~60s to ~20s on my cygwin machine, and from ~15s to ~9s on a linux VM running on the
    same hardware
    
    v2: AS_TR_SH transforms characters which are invalid in shell variable names, so we don't
    have to use sed to transform spaces ourself
    
    Signed-off-by: Jon TURNEY <jon.turney at dronecode.org.uk>
    Reviewed-by: Gaetan Nadon <memsize at videotron.ca>